Final answer:
To predict when a stock price will double based on a line of best fit, historical price data and regression analysis are needed.
Step-by-step explanation:
The question prompt does not provide any information about a specific stock or its price data for 2015. However, if we had access to the stock's historical price data, we could use a line of best fit (also known as a trendline) to predict the future prices of the stock. To determine in what year the line of best fit predicts the stock price to double, we would need to find the year when the predicted price is twice the price in 2015. For example, let's say that the line of best fit predicts the stock price to double in the year 2023. This means that the predicted price in 2023 would be twice the price in 2015. It's important to note that the accuracy of the prediction depends on the quality and reliability of the data used to create the line of best fit, as well as any assumptions made in the analysis. Predicting stock prices is a complex task and involves several factors, so it's always advisable to consult professional financial advisors or utilize advanced models and tools for more accurate predictions.